Biomedical subjects

M Ueda

Publications and source records attributed to M Ueda.

At least 181 records · Page 10Linked to original sources

PubMed1997

Involvement of prostaglandin E2 in rabbit corneal injury by anterior segment ischaemia.

The involvement of prostaglandins (PGs) in the development of anterior segment ischaemia after occlusion of the bilateral long posterior ciliary arteries was investigated in rabbit eyes. In this experimental ischaemia, the tissue weight and protein content in the peripheral cornea and the protein content in the aqueous humour increased on the first postoperative day. Topically applied cyclooxygenase inhibitor diclofenac (0.1%) reduced corneal inflammation and further suppressed the elevation in the tissue weight and protein content in the peripheral cornea on day 1 after ischaemia, but did not affect the changes in the aqueous humour. Subconjunctivally administered PGE1 and PGE2 induced corneal oedema and increased corneal protein content in diclofenac-treated and ischaemia-induced eyes, but PGD2, PGF2alpha, and the stable PGI2 analogue cicaprost did not evoke any change. In fact, PGE2 content was markedly increased in the aqueous humour on day 1 after ischaemia, and diclofenac suppressed the increase. In addition, CPT-cAMP increased the corneal tissue weight and protein content in organ culture. These observations suggest that PGE2 may play an important role in developing corneal oedema at the initial stage of ischaemic damage, possibly through the cAMP-mediated pathway.

Alprostadil↗

PubMed1997

Clinical results of cultured epithelial cell grafting in the oral and maxillofacial region.

Cultured epithelium has proven to be a good grafting material for skin defects. In our experience two kinds of epithelial cells, skin keratinocytes and mucosal cells, have been used to fabricate cultured epithelial sheets and autografted to the patients. Traumatic scars of the face were treated by cultured epidermal epithelium (CEE). The skin graft in the oral cavity was replaced by mucosa using cultured mucosal epithelium (CME). Also, the CME was applied to the skin defects at the donor sites of split-thickness skin grafts. Postsurgical follow-up showed good results. As a result, CME was useful in improving the biological environment around the abutments of dental implants, and it also promoted the re-epithelialization of skin defects. From our investigations, CEE/CME are promising treatment modalities which can reduce pain and speed up the healing process in burn patients. Therefore, cultured epithelium banks are worth establishing for auto- and allografting of skin/mucosal defects.

Adult↗

PubMed1997

Trifocal distraction osteogenesis for segmental mandibular defect: a technical innovation.

Distraction osteogenesis in the mandible is a promising method, not only for correction of mandibular hypoplasia such as hemifacial microsomia, but also for reconstruction of segmental bone defects in the mandible. The authors report a case in which a mandibular segmental defect, about 60 mm in length, was reconstructed by distraction osteogenesis. The patient was a 45-year-old man who had been treated for an oral floor cancer. After preoperative chemotherapy and irradiation therapy, the mandible had been resected from the second incisor on the right side to the first molar on the left side, and had been reconstructed with a titanium plate and a vascularized rectus-abdominis compound flap. However, an infection developed around the titanium plate and this plate had to be removed. Therefore, trifocal distraction using an original three-dimensional distractor was performed, at the rate of 1 mm per day (0.5 mm in the morning and 0.5 mm in the evening). During the distraction period, the skin flap was pushed out from the bone defect. Although small free bone transplants were needed for complete continuity, the segmental bone defect was almost filled by the regenerated bone with the lengthened gingiva. Radiographic observation showed successful new bone formation in the lengthened area.

Bone Plates↗

PubMed1997

Maxillary advancement by distraction osteogenesis using osseointegrated implants.

The purpose of this study was to establish a new technique for distraction osteogenesis in the maxilla, using an osseointegrated implant and intraoral device. After extraction of the premolar and molar teeth, four titanium implants were installed in the maxillary alveolar bone. Three months later, the distraction device was connected to the abutments, and osteotomy in the medial portion of maxilla between the implants was performed. Distraction was carried out at the rate of 1 mm per day to obtain a 10-mm elongation, Morphological, radiographic and histological examinations showed that successful maxillary advancement was achieved. New bone was primarily formed by intramembranous ossification and partial endochondral ossification. Titanium implants placed for anchorage of the distraction device remained stable during the course of maxillary advancement. This technique can provide significant advancement of the maxilla with better stability. The treatment system can be applied in any kind of maxillary deformities which need to be corrected surgically by classic osteotomy without bone grafting.

Alveolar Process↗

PubMed1997

Surgical treatment of cancer of the thoracic esophagus in association with a major pulmonary operation.

BACKGROUND: Pulmonary complications have been a major cause of mortality after operations for cancer of the thoracic esophagus. Although the risk involved in esophagectomy associated with a major pulmonary operation is expected to be high, it has seldom been evaluated on the basis of clinical experience. STUDY DESIGN: Of 408 patients who underwent esophagectomy, 8 had previously undergone major pulmonary operation (7 for tuberculosis and 1 for pulmonary cancer) and 10 underwent concurrent major pulmonary resection (7 for pulmonary invasion of esophageal cancer, 2 for synchronous pulmonary cancer, 1 for extensive bronchiectasia). All patients underwent systematic lymph node dissection for esophageal cancer, except one patient with mucosal cancer. To prevent postoperative complications, the operative approach and dissection procedures for esophageal cancer were modified according to the associated pulmonary operation and the extent of cancer invasion. All thoracotomies for esophagectomy were performed on the same side as the major pulmonary operation. Additional median sternotomy was performed when necessary. In the most recent 8 patients who underwent major pulmonary resection concurrent with esophagectomy, the bronchial stump was covered with a pedicle flap. RESULTS: Of the 18 patients who underwent pulmonary operation, postoperative complications developed in 13 of the 18 object patients, but none was fatal. The 3-year survival rate was 45%. All deaths were caused by esophageal cancer or another cancer. CONCLUSIONS: Aggressive esophagectomy associated with major pulmonary operation is not contraindicated in patients with fair risk conditions. The operative procedures for esophagectomy should be appropriately modified to minimize the effect of the associated pulmonary operation. Special care should be taken with respect to the approach for mediastinal dissection and closure of the bronchial stump.

Combined Modality Therapy↗

PubMed1997

A comparative study of removal torque of endosseous implants in the fibula, iliac crest and scapula of cadavers: preliminary report.

This study was undertaken to compare removal torque of endosseous implants in the fibula, iliac crest and scapula of cadavers. The fibulae, iliac crests and scapulae were harvested from the right side of 5 formalin-preserved cadavers. Endosseous implants (Brånemark System) were placed at 3 points of each bone. The removal torque of the implant was measured by a torque gauge manometer (Tohnichi 15 BTG-N). After measurement of the removal torque, the bone was cut at each implant site. The thicknesses of cortical and total bone were measured. The mean removal torques were 46.3 N cm in the fibulae, 15.2 N cm in the iliac crests and 21.4 N cm in the scapulae. There was a statistically significant difference in mean removal torque between the three bones. The total bone thicknesses were 11.7 mm in the fibulae, 9.9 mm in the iliac crests and 8.2 mm in the scapulae. The cortical bone thicknesses were 5.0 mm in the fibulae, 1.6 mm in the iliac crests and 1.8 mm in the scapulae. Significant correlation between the removal torque and the cortical bone thickness was found. However there was no significant correlation between the removal torque and the total bone thickness. In conclusion, the implants inserted in the fibulae showed the highest removal torques as compared to the ones inserted in the iliac crests and the scapulae. Moreover the removal torque was related to the thickness of the cortical bone in the implant sites.

Adult↗

PubMed1997

Differential diagnosis of tumours of the minor salivary glands of the palate by computed tomography.

OBJECTIVE: To define the CT criteria for differentiating malignant from benign tumours of the minor salivary glands of the palate and to evaluate their accuracy. PATIENTS AND METHODS: CT findings of 63 patients with histopathologically proven minor salivary gland tumours of the palate (23 malignant, 40 benign) were retrospectively evaluated. RESULTS: Aggressive bone destruction was a specific finding of malignant tumours, but was seen in only 57% (13/23) of this series. Extension into the pterygopalatine fossa was observed in seven malignant and one benign tumour. Calcifications within a tumour were observed in four cases, all of which were malignant. These three CT findings were significantly more frequent in malignant tumours. Using any one of these as the criterion for the malignancy, the sensitivity was 78% (18/23), specificity 98% (39/40) and accuracy 90% (57/63). CONCLUSION: Malignant tumours of the minor salivary glands of the palate are very likely to show any or all of aggressive bone destruction, extension into the pterygopalatine fossa and calcification, whereas benign tumours can almost always be correctly diagnosed by their absence.

Calcinosis↗

PubMed1997

Integrin alpha5 is expressed on human luteinizing granulosa cells during corpus luteum formation, and its expression is enhanced by human chorionic gonadotrophin in vitro.

We previously reported that human granulosa cells (GC) express integrin alpha6beta1, in large follicles and early corpus luteum (CL). In this study, we examined the expression of integrin alpha5 and fibronectin (FN) by immunohistochemistry. Integrin alpha5 was undetectable on human GC in preovulatory follicles, but it was intensely expressed on luteinizing GC of CL in the early luteal phase, and it was weakly expressed on large luteal cells (LL) in the midluteal phase. FN was similarly expressed between GC/LL. Thus, integrin alpha5 and FN were stage-specifically expressed on/between luteinizing GC in the early luteal phase. Next we examined the effect of human chorionic gonadotrophin (HCG) on expression of integrin alpha5 on luteinizing GC in vitro. GC obtained from preovulatory follicles were cultured for 3 days without (control) or with HCG (1 IU/ml), and expression of integrin alpha5 was examined by flow cytometry. Although the positivity rate did not differ, the mean relative fluorescence intensity was 3.4-fold higher in the HCG-treated group (n = 8, P < 0.01). These findings indicate that integrin alpha5 is rapidly expressed on GC during luteinization, probably under LH stimulation, and suggest that integrin alpha5 is involved in CL formation via interaction with its ligand FN.

Antigens, CD↗

PubMed1997

Immunohistochemical localization of the LH/HCG receptor in human ovary: HCG enhances cell surface expression of LH/HCG receptor on luteinizing granulosa cells in vitro.

We examined the immunohistochemical localization of luteinizing hormone (LH)/human chorionic gonadotrophin (HCG) receptor (LH-R) in the human ovary using the anti-human LH-R monoclonal antibody, 3B5. In the antral follicles, LH-R was detected on theca interna cells. In pre-ovulatory follicles, granulosa cells also expressed LH-R. During corpus luteum formation, granulosa cells seemed to increase the expression of LH-R, and in corpus luteum of mid-luteal phase, large luteal cells expressed LH-R more intensely than small luteal cells. In the regressing corpus luteum, LH-R was almost undetectable on both luteal cells, whereas in the corpus luteum of early pregnancy, LH-R continued to be expressed on large luteal cells. The granulosa cells obtained from the patients undergoing in-vitro fertilization therapy were cultured for 3 days in serum-free medium, without or with HCG (10 IU/ml) and tumour necrosis factor (TNF)alpha (10 ng/ml). Flow cytometry showed that the expression of LH-R on the cell surface of luteinizing granulosa cells was enhanced by HCG, but was unaffected by TNFalpha. These results suggest that the main target cells for LH/HCG change from theca interna cells/small luteal cells to granulosa cells/large luteal cells during ovulation, corpus luteum formation, and differentiation into the corpus luteum of pregnancy, probably under the influence of LH/HCG.

Adolescent↗

PubMed1997

Evaluation of peroxisomal heme in yeast.

Heme is supposed to be transported into peroxisomes to form peroxisomal catalase [EC 1.11.1.6] in harmony with proliferation of the organelle because of the absence of the heme synthetic pathway in peroxisomes. We tried to understand the transport mechanism of peroxisomal catalase through the peroxisomal membrane from the aspects of a cofactor, heme, by measuring cellular and subcellular heme contents with the pyridine hemochrome method, independent of measuring the catalase activity. n-Alkane-grown Candida tropicalis cells, in which peroxisomes develop profusely, contained a larger amount of heme than the glucose-grown cells, and the increase well matched that of the catalase activity. The results of subcellular fractionation of the n-alkane-grown cells showed that, in peroxisomes, the catalase subunit and heme existed in a molar ratio of 1:1, indicating that excessively transported catalase subunit proteins or heme could not be present in peroxisomes and they formed a tetramer having four molecules of heme. From this quantification of peroxisomal heme, it was strongly suggested that the amounts of the catalase subunit protein and heme transported into peroxisomes should be stoichiometrically regulated at the step of their synthesis or/and transport.

Alkanes↗

PubMed1997

Expression of acetoacetyl-CoA thiolase isozyme genes of n-alkane-assimilating yeast, Candida tropicalis: isozymes in two intracellular compartments are derived from the same genes.

In the n-alkane-assimilating yeast Candida tropicalis, there are two isozymes of acetoacetyl-CoA thiolase, peroxisomal acetoacetyl-CoA thiolase (peroxisomal Thiolase I), and cytosolic acetoacetyl-CoA thiolase (cytosolic Thiolase I). We have previously isolated two genes (CT-T1A and CT-T1B) which encode Thiolase I. In order to compare the expressed products of Thiolase I isozyme-encoding genes in C. tropicalis, cytosolic Thiolase I was first purified from glucose-grown C. tropicalis in which the proliferation of peroxisomes and the expression of peroxisomal Thiolase I were repressed. Cytosolic Thiolase I was virtually identical to peroxisomal Thiolase I in molecular mass, kinetic and immunochemical properties, and primary structure at the N-terminus. Amino acid sequence analysis revealed that cytosolic Thiolase I was the mixture of products of two genes (CT-T1A and CT-T1B), as in the case of the peroxisomal enzyme. CT-T1A and CT-T1B were expressed independently in the yeast Saccharomyces cerevisiae and the recombinant proteins were purified. Recombinant Thiolase IA and IB exhibited practically identical enzymatic properties to cytosolic and peroxisomal Thiolase Is from C. tropicalis. These results revealed that cytosolic Thiolase I and peroxisomal Thiolase I were encoded not by different genes, but by the same genes (CT-T1A and CT-T1B) and are present as a mixture of products expressed by both genes, although their subcellular localizations are different.

Acetyl-CoA C-Acetyltransferase↗

PubMed1997

Experimental study of distraction osteogenesis in the maxillofacial region.

A cylindrical incision was made in the calvarial bone of mongrel dogs. Using a distraction device that used bone-connecting implants as supports, vertical distraction osteogenesis of calvarial bone was performed. Calvarial bone was distracted vertically at a speed of 0.5 mm per day, making enlargement of the cranium possible. The gap that resulted from distraction was closed with newly formed bone. The implants made a solid connection with no oscillation or dislodgment from the external pressure used for distraction. Our results show that vertical distraction of thin calvarial bone can be done using osseointegrated implants as supports. This indicates the possibility of broadening the applications of this method to plastic correction of craniomaxillofacial bone.

Animals↗

PubMed1997

Enhanced expression of angiotensin-converting enzyme is associated with progression of coronary atherosclerosis in humans.

BACKGROUND: The clinical usefulness of angiotensin converting enzyme (ACE) inhibitors in preventing the recurrence of myocardial infarction has been investigated in large randomized trials. Results from many studies using animal models have suggested that ACE inhibitors have vasculoprotective effects, which may contribute to the prevention of coronary atherosclerosis. OBJECTIVE: To examine the association between vascular angiotensin generation and the development of coronary atherosclerosis in humans. METHODS: We used immunocytochemical techniques to examine frozen sections from 44 coronary artery segments from 19 corpses. RESULTS: Three segments were sites of plaque rupture in patients who had died from acute myocardial infarction. Other specimens of coronary artery segments were characterized histologically to be normal artery segments with diffuse intimal thickening (n = 6), hypercellular lesions composed of smooth muscle cells with or without infiltration of macrophages (n = 11), atheromatous plaque (n = 12), and fibrosclerotic plaque (n = 12). In normal arteries with diffuse intimal thickening, ACE was expressed in endothelial cells. In those with hypercellular lesions and atheromatous plaques, however, enhanced ACE expression was found in macrophages and smooth muscle cells. In contrast, arteries with fibrosclerotic plaques exhibited little or no ACE expression within the plaque. All three ruptured plaques expressed ACE strongly in macrophages accumulated around the attenuated fibrous cap. CONCLUSION: The strong association of enhanced ACE expression with the histologic characteristics of plaques suggests that ACE in hypercellular lesions, atheromatous plaques, and ruptured plaques contributes greatly to the further progression of atherosclerosis via an increase in vascular angiotensin II formation and inactivation of bradykinin.

Adult↗

PubMed1997

Pharmacological studies on a new antihypertensive agent, S-2150, a benzothiazepine derivative: 3. Hypotensive and antimyocardial-stunning effects in dogs.

The hypotensive and antimyocardial-stunning effects of a new 1,5-benzothiazepine antihypertensive agent, S-2150, were investigated in dogs. S-2150 (30 mg/kg, p.o.) decreased the blood pressure in conscious renal hypertensive dogs. Although the maximal hypotensive effect of S-2150 was observed at 5-9 h after administration, the effect of diltiazem was seen at 2.0 h. Arrhythmia was not observed as a hypotensive effects of S-2150 but was markedly induced by diltiazem. In anesthetized open-chest dogs, S-2150 (20 micrograms/kg/min, i.v.) caused by hypotensive effect similar to that of diltiazem but decreased myocardial work (double product) by much less than did diltiazem. S-2150 more promptly improved the local myocardial stunning caused by occlusion of the left anterior descending coronary artery and its reperfusion. This effect did not accompany the energy-sparing action in ischemic/reperfused myocardium, which was different from the case of diltiazem. In isolated dog mesenteric arteries, S-2150 relaxed KCl and phenylephrine contracture. These results suggest that S-2150 is a favorable hypotensive agent for hypertensive patients with ischemic heart disease. Blockage of both Ca2+ channels and alpha 1-adrenoceptors by S-2150 seems to lead to cardiovascular effects different from those of diltiazem.

Adenosine Triphosphate↗

PubMed1997

Expression of fibroblast growth factor receptors in naevus-cell naevus and malignant melanoma.

In a previous study, we showed by immunohistochemical analysis that basic fibroblast growth factor (bFGF) is expressed strongly and homogeneously in naevus-cell naevus (NCN), while that in malignant melanoma (MM) is heterogeneous and sometimes non-existent. In order to elucidate the role of bFGF in these pigmented tumours, the expression of its receptors must be determined. In this study, we performed an immunohistochemical analysis of FGF receptors 1, 2 and 3 (FGFR-1, FGFR-2 and FGFR-3, respectively) in NCN and MM and compared their expression and localization with those of bFGF. The expression of bFGF and its three receptors was also examined in melanoma cell lines. None of the 10 NCN that showed strong, homogeneous staining for bFGF expressed FGFR-1 or FGFR-3 proteins; six weakly expressed FGFR-2 protein. Ten primary and 10 metastatic MM showed heterogeneous expression for the three receptors, with larger populations of FGFR-3-negative cells in the primary than in the metastatic tumours. Western blot analysis showed homogeneous expression of bFGF protein in all four melanoma cell lines tested, while FGFR proteins had a heterogeneous distribution in the different cell lines. Cultured NCN and normal melanocytes showed no immunoreactive band for FGFR-1 protein, the only protein tested. Our results suggested that tumour-derived bFGF is involved in melanoma formation through an autocrine mechanism, but is involved mostly through a paracrine or other mechanisms in NCN.

Blotting, Western↗

PubMed1997

Implant-supported prostheses after maxillary cancer resection: preliminary report.

A preliminary study of 4 partial maxillectomy patients who received a total of 17 endosseous implants and implant-supported prostheses after oral cancer resection is reported. The masticatory function index (chewing efficiency) after implant placement was higher than the preoperative value. Speech with an implant-supported prosthesis improved as compared with previous prostheses or without a prosthesis. All of the patients received radiation and adjunctive hyperbaric oxygen therapy. The success rate after a 2-year follow-up period was 88.2 percent.

Aged↗

PubMed1997

Cytologic evaluation of conjunctival epithelium using Cytobrush-S: value of slide preparation by ThinPrep technique.

Recent clinical trials have indicated that an automated smear apparatus (ThinPrep process) of sample preparation has great diagnostic sensitivity. In this study, conjunctival brush cytology prepared using the ThinPrep method was applied in ocular surface disorders especially for dry eye status. To assess its diagnostic value in cellular samples, 17 patients with keratoconjunctivitis sicca (KCS) and 10 normal volunteer patients were examined using this technique. Conjunctival cells from normal controls revealed fine chromatin and polyhedral cytoplasm without having keratinized cytoplasm. On the other hand, the cellular samples from KCS revealed increased keratinized cells with pyknotic nuclei. They also contained extremely elongated cells. In KCS patients, the mean number of keratinized cells was significantly higher (34.1 cells/300 cells) than that of the normal control group (0.2 cells/300 cells). In patients with KCS, inflammatory cell counts were also higher than those of normal controls. Conjunctival cytology by means of the ThinPrep method obviously deserves additional trials as an adjunct in the cytology of dry eye states, especially in quantitative ocular evaluation for various ocular lesions.

Conjunctiva↗

PubMed1997

Outcomes of infants whose mothers are positive for human herpesvirus-6 DNA within the genital tract in early gestation.

It has been reported that HHV-6 (human herpesvirus-6) DNA has been identified within the female genital tract. However, the clinical significance of this finding has been unclear. The clinical outcome of the presence of HHV-6 DNA in the genital tract of pregnant women on their infants was evaluated in the present study. One hundred and ten pregnant women were enrolled. Vaginal swabs were collected between 4 and 8 weeks of gestation and the presence or absence of HHV-6 DNA was evaluated by nested polymerase chain reaction (nPCR). The swabs were cultured to isolate the virus. The women were divided into two groups: HHV-6 DNA-positive, and negative. The outcome variables of the infants of these two groups were statistically estimated at birth and at 1 month of age. Saliva and blood cells were collected from the infants at birth and at 1 month of age and were also evaluated by nPCR. HHV-6 DNA was detected in the vaginal swabs of 28 pregnant women (25.5%), but was not detected in any other samples, including saliva and blood cells from their infants. Virus could not be isolated from any vaginal samples. Any outcome variables were not significantly different between the two groups. The presence of HHV-6 DNA within the genital tract of pregnant women did not affect the health of their infants. It is suggested that HHV-6 transmission to infants through the genital tract of their mothers during pregnancy does not occur, or only very rarely.

Adult↗